[TR] TR4A Parking Lights

G.D. Huggins gdhuggins at genfiniti.com
Sun Nov 3 06:32:12 MST 2019


I am having a curious issue with my parking lights, which started all of the sudden after eight years of reliable performance.
I was out on one of my night drives, and getting out of the car, noticed that the parking lights were not on, yet the headlights were.
I drove home that night with the hazards on, which indicated that they do in fact work.

When I started troubleshooting the problem, I removed the steering wheel and switch escutcheons, and inspected the switch itself.
It looked good so I remounted it, and put it all back together.  Still no luck.

Accidentally, I jostled the bell-shaped upper part of the steering column to which the switches are secured, and they came on!
On closer inspection, that bell-shaped part is separate of the main steering column, and had become loose.
I manipulated that bell section and the parking lights would come on, or go off, depending on what I was doing.

So my question is...

Does the light switch need to be grounded?  I see no ground on the electrical schematics, but this behavior suggests that as I fiddle with that bell-shaped part, it is making or breaking a ground connection to the main steering column, which has a ground strap near the steering rack.  If this were true, then the ground sequence would be the switch mounted into the bell part via the upper and lower bolts, the bell itself friction grounded to the main steering column, the main steering column grounded to the rack.  But again, I don’t see any deliberate ground for the switch in the schematic.

Since the headlights come on, and stay on regardless of what the parking lights are doing, and the parking lights do shine with the bell is in the “correct” place, I believe it is safe to believe the switch itself is fine, as it behaves as expected.  Power is coming into the switch, and being “switched” to both the headlights and the parking lights.  It's just that those parking lights seem fickle depending on how that bell is fit inside the main steering column.

Thanks in advance.


Guy D. Huggins
1965 Triumph TR4A
CTC 63569LO

Online project diary at http://www.genfiniti.com/triumph

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